1 /*-
2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
3 *
4 * Copyright (c) 1996 - 2001 Brian Somers <[email protected]>
5 * based on work by Toshiharu OHNO <[email protected]>
6 * Internet Initiative Japan, Inc (IIJ)
7 * All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 *
30 * $FreeBSD$
31 */
32
33 #include <sys/param.h>
34 #include <netinet/in.h>
35 #include <netinet/in_systm.h>
36 #include <netinet/ip.h>
37 #include <sys/un.h>
38 #include <sys/socket.h>
39 #include <net/route.h>
40
41 #include <errno.h>
42 #include <fcntl.h>
43 #include <paths.h>
44 #include <signal.h>
45 #include <stdarg.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49 #include <sys/time.h>
50 #include <termios.h>
51 #include <unistd.h>
52 #include <sys/stat.h>
53
54 #ifndef NONAT
55 #ifdef LOCALNAT
56 #include "alias.h"
57 #else
58 #include <alias.h>
59 #endif
60 #endif
61
62 #include "layer.h"
63 #include "probe.h"
64 #include "mbuf.h"
65 #include "log.h"
66 #include "defs.h"
67 #include "id.h"
68 #include "timer.h"
69 #include "fsm.h"
70 #include "lqr.h"
71 #include "hdlc.h"
72 #include "lcp.h"
73 #include "ccp.h"
74 #include "iplist.h"
75 #include "throughput.h"
76 #include "slcompress.h"
77 #include "ncpaddr.h"
78 #include "ipcp.h"
79 #include "filter.h"
80 #include "descriptor.h"
81 #include "link.h"
82 #include "mp.h"
83 #ifndef NORADIUS
84 #include "radius.h"
85 #endif
86 #include "ipv6cp.h"
87 #include "ncp.h"
88 #include "bundle.h"
89 #include "auth.h"
90 #include "systems.h"
91 #include "sig.h"
92 #include "main.h"
93 #include "server.h"
94 #include "prompt.h"
95 #include "chat.h"
96 #include "chap.h"
97 #include "cbcp.h"
98 #include "datalink.h"
99 #include "iface.h"
100
101 #ifndef O_NONBLOCK
102 #ifdef O_NDELAY
103 #define O_NONBLOCK O_NDELAY
104 #endif
105 #endif
106
107 static void DoLoop(struct bundle *);
108 static void TerminalStop(int);
109
110 static struct bundle *SignalBundle;
111 static struct prompt *SignalPrompt;
112 struct libalias *la;
113
114 void
Cleanup()115 Cleanup()
116 {
117 SignalBundle->CleaningUp = 1;
118 bundle_Close(SignalBundle, NULL, CLOSE_STAYDOWN);
119 }
120
121 void
AbortProgram(int excode)122 AbortProgram(int excode)
123 {
124 if (SignalBundle)
125 server_Close(SignalBundle);
126 log_Printf(LogPHASE, "PPP Terminated (%s).\n", ex_desc(excode));
127 if (SignalBundle) {
128 bundle_Close(SignalBundle, NULL, CLOSE_STAYDOWN);
129 bundle_Destroy(SignalBundle);
130 }
131 log_Close();
132 exit(excode);
133 }
134
135 static void
CloseConnection(int signo)136 CloseConnection(int signo)
137 {
138 /* NOTE, these are manual, we've done a setsid() */
139 sig_signal(SIGINT, SIG_IGN);
140 log_Printf(LogPHASE, "Caught signal %d, abort connection(s)\n", signo);
141 bundle_Down(SignalBundle, CLOSE_STAYDOWN);
142 sig_signal(SIGINT, CloseConnection);
143 }
144
145 static void
CloseSession(int signo)146 CloseSession(int signo)
147 {
148 log_Printf(LogPHASE, "Signal %d, terminate.\n", signo);
149 Cleanup();
150 }
151
152 static pid_t BGPid = 0;
153
154 static void
KillChild(int signo)155 KillChild(int signo)
156 {
157 signal(signo, SIG_IGN);
158 log_Printf(LogPHASE, "Parent: Signal %d\n", signo);
159 kill(BGPid, SIGINT);
160 }
161
162 static void
TerminalCont(int signo __unused)163 TerminalCont(int signo __unused)
164 {
165 signal(SIGCONT, SIG_DFL);
166 prompt_Continue(SignalPrompt);
167 }
168
169 static void
TerminalStop(int signo __unused)170 TerminalStop(int signo __unused)
171 {
172 prompt_Suspend(SignalPrompt);
173 signal(SIGCONT, TerminalCont);
174 raise(SIGSTOP);
175 }
176
177 static void
BringDownServer(int signo __unused)178 BringDownServer(int signo __unused)
179 {
180 /* Drops all child prompts too ! */
181 if (server_Close(SignalBundle))
182 log_Printf(LogPHASE, "Closed server socket\n");
183 }
184
185 static void
RestartServer(int signo __unused)186 RestartServer(int signo __unused)
187 {
188 /* Drops all child prompts and re-opens the socket */
189 server_Reopen(SignalBundle);
190 }
191
192 static void
Usage(void)193 Usage(void)
194 {
195 fprintf(stderr, "usage: ppp [-auto | -foreground | -background | -direct |"
196 " -dedicated | -ddial | -interactive]"
197 #ifndef NONAT
198 " [-nat]"
199 #endif
200 " [-quiet] [-unit N] [system ...]\n");
201 exit(EX_START);
202 }
203
204 struct switches {
205 unsigned nat : 1;
206 unsigned fg : 1;
207 unsigned quiet : 1;
208 int mode;
209 int unit;
210 };
211
212 static int
ProcessArgs(int argc,char ** argv,struct switches * sw)213 ProcessArgs(int argc, char **argv, struct switches *sw)
214 {
215 int optc, newmode, arg;
216 char *cp;
217
218 optc = 0;
219 memset(sw, '\0', sizeof *sw);
220 sw->mode = PHYS_INTERACTIVE;
221 sw->unit = -1;
222
223 for (arg = 1; arg < argc && *argv[arg] == '-'; arg++, optc++) {
224 cp = argv[arg] + 1;
225 newmode = Nam2mode(cp);
226 switch (newmode) {
227 case PHYS_NONE:
228 if (strcmp(cp, "nat") == 0) {
229 #ifdef NONAT
230 log_Printf(LogWARN, "%s ignored: NAT is compiled out\n", argv[arg]);
231 #else
232 sw->nat = 1;
233 #endif
234 optc--; /* this option isn't exclusive */
235 } else if (strcmp(cp, "alias") == 0) {
236 #ifdef NONAT
237 log_Printf(LogWARN, "%s ignored: NAT is compiled out\n", argv[arg]);
238 fprintf(stderr, "%s ignored: NAT is compiled out\n", argv[arg]);
239 #else
240 log_Printf(LogWARN, "%s is deprecated\n", argv[arg]);
241 fprintf(stderr, "%s is deprecated\n", argv[arg]);
242 sw->nat = 1;
243 #endif
244 optc--; /* this option isn't exclusive */
245 } else if (strncmp(cp, "unit", 4) == 0) {
246 optc--; /* this option isn't exclusive */
247 if (cp[4] == '\0') {
248 optc--; /* nor is the argument */
249 if (++arg == argc) {
250 fprintf(stderr, "-unit: Expected unit number\n");
251 Usage();
252 } else
253 sw->unit = atoi(argv[arg]);
254 } else
255 sw->unit = atoi(cp + 4);
256 } else if (strcmp(cp, "quiet") == 0) {
257 sw->quiet = 1;
258 optc--; /* this option isn't exclusive */
259 } else
260 Usage();
261 break;
262
263 case PHYS_ALL:
264 Usage();
265 break;
266
267 default:
268 sw->mode = newmode;
269 if (newmode == PHYS_FOREGROUND)
270 sw->fg = 1;
271 }
272 }
273
274 if (optc > 1) {
275 fprintf(stderr, "You may specify only one mode.\n");
276 exit(EX_START);
277 }
278
279 if (sw->mode == PHYS_AUTO && arg == argc) {
280 fprintf(stderr, "A system must be specified in auto mode.\n");
281 exit(EX_START);
282 }
283
284 return arg; /* Don't SetLabel yet ! */
285 }
286
287 static void
CheckLabel(const char * label,struct prompt * prompt,int mode)288 CheckLabel(const char *label, struct prompt *prompt, int mode)
289 {
290 const char *err;
291
292 if ((err = system_IsValid(label, prompt, mode)) != NULL) {
293 fprintf(stderr, "%s: %s\n", label, err);
294 if (mode == PHYS_DIRECT)
295 log_Printf(LogWARN, "Label %s rejected -direct connection: %s\n",
296 label, err);
297 log_Close();
298 exit(1);
299 }
300 }
301
302
303 int
main(int argc,char ** argv)304 main(int argc, char **argv)
305 {
306 char *name;
307 const char *lastlabel;
308 int arg, holdfd[3], label;
309 unsigned f;
310 struct bundle *bundle;
311 struct prompt *prompt;
312 struct switches sw;
313
314 probe_Init();
315
316 /*
317 * We open 3 descriptors to ensure that STDIN_FILENO, STDOUT_FILENO and
318 * STDERR_FILENO are always open. These are closed before DoLoop(),
319 * but *after* we've avoided the possibility of erroneously closing
320 * an important descriptor with close(STD{IN,OUT,ERR}_FILENO).
321 */
322 if ((holdfd[0] = open(_PATH_DEVNULL, O_RDWR)) == -1) {
323 fprintf(stderr, "Cannot open %s !\n", _PATH_DEVNULL);
324 return 2;
325 }
326 for (f = 1; f < sizeof holdfd / sizeof *holdfd; f++)
327 holdfd[f] = dup(holdfd[0]);
328
329 name = strrchr(argv[0], '/');
330 log_Open(name ? name + 1 : argv[0]);
331
332 #ifndef NONAT
333 la = LibAliasInit(NULL);
334 #endif
335 label = ProcessArgs(argc, argv, &sw);
336
337 /*
338 * A FreeBSD & OpenBSD hack to dodge a bug in the tty driver that drops
339 * output occasionally.... I must find the real reason some time. To
340 * display the dodgy behaviour, comment out this bit, make yourself a large
341 * routing table and then run ppp in interactive mode. The `show route'
342 * command will drop chunks of data !!!
343 */
344 if (sw.mode == PHYS_INTERACTIVE) {
345 close(STDIN_FILENO);
346 if (open(_PATH_TTY, O_RDONLY) != STDIN_FILENO) {
347 fprintf(stderr, "Cannot open %s for input !\n", _PATH_TTY);
348 return 2;
349 }
350 }
351
352 /* Allow output for the moment (except in direct mode) */
353 if (sw.mode == PHYS_DIRECT)
354 prompt = NULL;
355 else
356 SignalPrompt = prompt = prompt_Create(NULL, NULL, PROMPT_STD);
357
358 ID0init();
359 if (ID0realuid() != 0) {
360 char conf[200], *ptr;
361
362 snprintf(conf, sizeof conf, "%s/%s", PPP_CONFDIR, CONFFILE);
363 do {
364 struct stat sb;
365
366 if (stat(conf, &sb) == 0 && sb.st_mode & S_IWOTH) {
367 log_Printf(LogALERT, "ppp: Access violation: Please protect %s\n",
368 conf);
369 return -1;
370 }
371 ptr = conf + strlen(conf)-2;
372 while (ptr > conf && *ptr != '/')
373 *ptr-- = '\0';
374 } while (ptr >= conf);
375 }
376
377 if (label < argc)
378 for (arg = label; arg < argc; arg++)
379 CheckLabel(argv[arg], prompt, sw.mode);
380 else
381 CheckLabel("default", prompt, sw.mode);
382
383 if (!sw.quiet)
384 prompt_Printf(prompt, "Working in %s mode\n", mode2Nam(sw.mode));
385
386 if ((bundle = bundle_Create(TUN_PREFIX, sw.mode, sw.unit)) == NULL)
387 return EX_START;
388
389 /* NOTE: We may now have changed argv[1] via a ``set proctitle'' */
390
391 SignalBundle = bundle;
392 bundle->NatEnabled = sw.nat;
393 if (sw.nat)
394 opt_enable(bundle, OPT_IFACEALIAS);
395
396 if (system_Select(bundle, "default", CONFFILE, prompt, NULL) < 0)
397 prompt_Printf(prompt, "Warning: No default entry found in config file.\n");
398
399 sig_signal(SIGHUP, CloseSession);
400 sig_signal(SIGTERM, CloseSession);
401 sig_signal(SIGINT, CloseConnection);
402 sig_signal(SIGQUIT, CloseSession);
403 sig_signal(SIGALRM, SIG_IGN);
404 signal(SIGPIPE, SIG_IGN);
405
406 if (sw.mode == PHYS_INTERACTIVE)
407 sig_signal(SIGTSTP, TerminalStop);
408
409 sig_signal(SIGUSR1, RestartServer);
410 sig_signal(SIGUSR2, BringDownServer);
411
412 lastlabel = argv[argc - 1];
413 for (arg = label; arg < argc; arg++) {
414 /* In case we use LABEL or ``set enddisc label'' */
415 bundle_SetLabel(bundle, lastlabel);
416 system_Select(bundle, argv[arg], CONFFILE, prompt, NULL);
417 }
418
419 if (label < argc)
420 /* In case the last label did a ``load'' */
421 bundle_SetLabel(bundle, lastlabel);
422
423 if (sw.mode == PHYS_AUTO &&
424 ncprange_family(&bundle->ncp.ipcp.cfg.peer_range) == AF_UNSPEC) {
425 prompt_Printf(prompt, "You must ``set ifaddr'' with a peer address "
426 "in auto mode.\n");
427 AbortProgram(EX_START);
428 }
429
430 if (prompt) {
431 prompt->bundle = bundle; /* couldn't do it earlier */
432 if (!sw.quiet)
433 prompt_Printf(prompt, "Using interface: %s\n", bundle->iface->name);
434 }
435
436 if (sw.mode != PHYS_INTERACTIVE) {
437 if (sw.mode != PHYS_DIRECT) {
438 if (!sw.fg) {
439 int bgpipe[2];
440 pid_t bgpid;
441
442 if (sw.mode == PHYS_BACKGROUND && pipe(bgpipe)) {
443 log_Printf(LogERROR, "pipe: %s\n", strerror(errno));
444 AbortProgram(EX_SOCK);
445 }
446
447 bgpid = fork();
448 if (bgpid == -1) {
449 log_Printf(LogERROR, "fork: %s\n", strerror(errno));
450 AbortProgram(EX_SOCK);
451 }
452
453 if (bgpid) {
454 char c = EX_NORMAL;
455 int ret;
456
457 if (sw.mode == PHYS_BACKGROUND) {
458 close(bgpipe[1]);
459 BGPid = bgpid;
460 /* If we get a signal, kill the child */
461 signal(SIGHUP, KillChild);
462 signal(SIGTERM, KillChild);
463 signal(SIGINT, KillChild);
464 signal(SIGQUIT, KillChild);
465
466 /* Wait for our child to close its pipe before we exit */
467 while ((ret = read(bgpipe[0], &c, 1)) == 1) {
468 switch (c) {
469 case EX_NORMAL:
470 if (!sw.quiet) {
471 prompt_Printf(prompt, "PPP enabled\n");
472 log_Printf(LogPHASE, "Parent: PPP enabled\n");
473 }
474 break;
475 case EX_REDIAL:
476 if (!sw.quiet)
477 prompt_Printf(prompt, "Attempting redial\n");
478 continue;
479 case EX_RECONNECT:
480 if (!sw.quiet)
481 prompt_Printf(prompt, "Attempting reconnect\n");
482 continue;
483 default:
484 prompt_Printf(prompt, "Child failed (%s)\n",
485 ex_desc((int)c));
486 log_Printf(LogPHASE, "Parent: Child failed (%s)\n",
487 ex_desc((int) c));
488 }
489 break;
490 }
491 if (ret != 1) {
492 prompt_Printf(prompt, "Child exit, no status.\n");
493 log_Printf(LogPHASE, "Parent: Child exit, no status.\n");
494 }
495 close(bgpipe[0]);
496 }
497 return c;
498 } else if (sw.mode == PHYS_BACKGROUND) {
499 close(bgpipe[0]);
500 bundle->notify.fd = bgpipe[1];
501 }
502
503 bundle_ChangedPID(bundle);
504 bundle_LockTun(bundle); /* we have a new pid */
505 }
506
507 /* -auto, -dedicated, -ddial, -foreground & -background */
508 prompt_Destroy(prompt, 0);
509 close(STDOUT_FILENO);
510 close(STDERR_FILENO);
511 close(STDIN_FILENO);
512 if (!sw.fg)
513 setsid();
514 } else {
515 /*
516 * -direct - STDIN_FILENO gets used by physical_Open. STDOUT_FILENO
517 * *may* get used in exec/pipe mode.
518 */
519 prompt_TtyInit(NULL);
520 close(STDERR_FILENO);
521 }
522 } else {
523 /* -interactive */
524 close(STDERR_FILENO);
525 prompt_TtyInit(prompt);
526 prompt_TtyCommandMode(prompt);
527 prompt_Required(prompt);
528 }
529
530 /* We can get rid of these now */
531 for (f = 0; f < sizeof holdfd / sizeof *holdfd; f++)
532 close(holdfd[f]);
533
534 log_Printf(LogPHASE, "PPP Started (%s mode).\n", mode2Nam(sw.mode));
535 DoLoop(bundle);
536 AbortProgram(EX_NORMAL);
537
538 return EX_NORMAL;
539 }
540
541 static void
DoLoop(struct bundle * bundle)542 DoLoop(struct bundle *bundle)
543 {
544 fd_set *rfds, *wfds, *efds;
545 int i, nfds, nothing_done;
546
547 if ((rfds = mkfdset()) == NULL) {
548 log_Printf(LogERROR, "DoLoop: Cannot create fd_set\n");
549 return;
550 }
551
552 if ((wfds = mkfdset()) == NULL) {
553 log_Printf(LogERROR, "DoLoop: Cannot create fd_set\n");
554 free(rfds);
555 return;
556 }
557
558 if ((efds = mkfdset()) == NULL) {
559 log_Printf(LogERROR, "DoLoop: Cannot create fd_set\n");
560 free(rfds);
561 free(wfds);
562 return;
563 }
564
565 for (; !bundle_IsDead(bundle); bundle_CleanDatalinks(bundle)) {
566 nfds = 0;
567 zerofdset(rfds);
568 zerofdset(wfds);
569 zerofdset(efds);
570
571 /* All our datalinks, the tun device and the MP socket */
572 descriptor_UpdateSet(&bundle->desc, rfds, wfds, efds, &nfds);
573
574 /* All our prompts and the diagnostic socket */
575 descriptor_UpdateSet(&server.desc, rfds, NULL, NULL, &nfds);
576
577 bundle_CleanDatalinks(bundle);
578 if (bundle_IsDead(bundle))
579 /* Don't select - we'll be here forever */
580 break;
581
582 /*
583 * It's possible that we've had a signal since we last checked. If
584 * we don't check again before calling select(), we may end up stuck
585 * after having missed the event.... sig_Handle() tries to be as
586 * quick as possible if nothing is likely to have happened.
587 * This is only really likely if we block in open(... O_NONBLOCK)
588 * which will happen with a misconfigured device.
589 */
590 if (sig_Handle())
591 continue;
592
593 i = select(nfds, rfds, wfds, efds, NULL);
594
595 if (i < 0 && errno != EINTR) {
596 log_Printf(LogERROR, "DoLoop: select(): %s\n", strerror(errno));
597 if (log_IsKept(LogTIMER)) {
598 struct timeval t;
599
600 for (i = 0; i <= nfds; i++) {
601 if (FD_ISSET(i, rfds)) {
602 log_Printf(LogTIMER, "Read set contains %d\n", i);
603 FD_CLR(i, rfds);
604 t.tv_sec = t.tv_usec = 0;
605 if (select(nfds, rfds, wfds, efds, &t) != -1) {
606 log_Printf(LogTIMER, "The culprit !\n");
607 break;
608 }
609 }
610 if (FD_ISSET(i, wfds)) {
611 log_Printf(LogTIMER, "Write set contains %d\n", i);
612 FD_CLR(i, wfds);
613 t.tv_sec = t.tv_usec = 0;
614 if (select(nfds, rfds, wfds, efds, &t) != -1) {
615 log_Printf(LogTIMER, "The culprit !\n");
616 break;
617 }
618 }
619 if (FD_ISSET(i, efds)) {
620 log_Printf(LogTIMER, "Error set contains %d\n", i);
621 FD_CLR(i, efds);
622 t.tv_sec = t.tv_usec = 0;
623 if (select(nfds, rfds, wfds, efds, &t) != -1) {
624 log_Printf(LogTIMER, "The culprit !\n");
625 break;
626 }
627 }
628 }
629 }
630 break;
631 }
632
633 log_Printf(LogTIMER, "Select returns %d\n", i);
634
635 sig_Handle();
636
637 if (i <= 0)
638 continue;
639
640 for (i = 0; i <= nfds; i++)
641 if (FD_ISSET(i, efds)) {
642 log_Printf(LogPHASE, "Exception detected on descriptor %d\n", i);
643 /* We deal gracefully with link descriptor exceptions */
644 if (!bundle_Exception(bundle, i)) {
645 log_Printf(LogERROR, "Exception cannot be handled !\n");
646 break;
647 }
648 }
649
650 if (i <= nfds)
651 break;
652
653 nothing_done = 1;
654
655 if (descriptor_IsSet(&server.desc, rfds)) {
656 descriptor_Read(&server.desc, bundle, rfds);
657 nothing_done = 0;
658 }
659
660 if (descriptor_IsSet(&bundle->desc, rfds)) {
661 descriptor_Read(&bundle->desc, bundle, rfds);
662 nothing_done = 0;
663 }
664
665 if (descriptor_IsSet(&bundle->desc, wfds))
666 if (descriptor_Write(&bundle->desc, bundle, wfds) <= 0 && nothing_done) {
667 /*
668 * This is disastrous. The OS has told us that something is
669 * writable, and all our write()s have failed. Rather than
670 * going back immediately to do our UpdateSet()s and select(),
671 * we sleep for a bit to avoid gobbling up all cpu time.
672 */
673 struct timeval t;
674
675 t.tv_sec = 0;
676 t.tv_usec = 100000;
677 select(0, NULL, NULL, NULL, &t);
678 }
679 }
680
681 log_Printf(LogDEBUG, "DoLoop done.\n");
682 }
683